Carburetor



March 2.6, 1968 B. WALKER v CARBURETOR Filed March 12, 1965 .vill

United States Patent Olice '3,374,991 Patented Mar. 26, 1968 3,374,991 CARBURETOR Brooks Walker, 1280 Columbus Ave., San Francisco, Calif. 94133 Filed Mar. 12, 1965, Ser. No. 439,168 4 Claims. (Cl. 261-41) ABSTRACT OF THE DISCLOSURE A carburetor for reducing the unburned hydrocarbons to reduce the smog producing components of an automobile engine exhaust. A conduit delivers a mixture of fuel and air to idle against a movable deflector near the center of the carburetor throat. Clean air is admitted when the deector is moved against the end of the conduit to shut off the ow of fuel and air mixture.

This invention pertains to improvements in carburetors that reduce the unburned hydrocarbons during different driving cycles to reduce the smog producing components of the automobile exhaust.

One feature is the mixing of the fuel to idle with the air to idle combined with the air to idle being brought in from outside the main air passage through the carburetor. This air to idle is mixed with the fuel to idle or a rich mixture of fuel and air that travels through a path from the float bowl to the engine side of the throttle valve in the carburetor. Certain air bleeds may be employed in this rich fuel and air to idle fuel path in the carburetor, such as the anti-Siphon bleed usually near the top of the goose neck in the idle fuel path and the transfer port usually just on the non-engine side of the throttle butterfly in a position to be passed over by the throttle butterfly when moving from a closed to an open position.

Another feature is to deliver the mixed fuel and air for idling by cond-uit to a place near the center of the carburetor main throat on the engine side of the throttle.

Another feature is to deliver such air and fuel intermixed in a more homogeneous manner at such central location. This idle system is an improvement over the usual present system where the mixture leaving a normal carburetor during idle operation results from a port admitting rich fuel and air at one side of the carburetor main throat on the engine side of the throttle valve and the main air to idle spilling around the edges of a cracked butterfly throttle, thereby supplying the fuel and air to idle the engine, as described in Glens Auto Repair Manual, 1962, pages 234, 235, paragraphs 3-42, 3-44, 3-45.

Another feature is the provision for killing most of the velocity of the air to idle in a direction straight across the main carburetor throat when leaving the auxiliary idle mixing tube by impinging such air and fuel on a deflector, the location of said deector being adjustably controlled from across said main carburetor throat from the entry of said fuel and air to idle through the idle mixing tube so as to adjust the distance of the deilector from the end of the mixing tube and thereby adjust the amount of mixed fuel and air to idle so as to provide an adjustment exterior of the carburetor to adjust the idle speed of the engine.

Another feature is the addition of more temperature increase to the main air to idle lbefore said idle air enters the idle fuel and air mixing tube than the temperature increase added to the air entering the carburetor main air horn for powerbeyond idling power, and to add such heat to the air to idle so as not to increase the temperature of the fuel in the float bowl which might cause boiling at the temperature desired for the air t idle.

Another feature is the provision of three adjustments for idling, a first one for controlling the rate of ilow of rich fuel and air from the carburetor float bowl, etc. and a second .adjustment controlling the rate of flow of mixed fuel and air to idle that is pre-mixed with the rich idle fuel and air, the third adjustment adjusting the idle air ow before it mixes with the rich fuel and air from the carburetor bowl and thereby acting as an adjustable choke to vary the suction on the rich fuel and air from the float bowl, the first and third adjustments adjusting the rich and lean of the idling mixture of fuel and air, the second controlling the amount of fuell and air to idle and therefore the rate of engine idle speed.

Another feature is the second adjustment being in the form of the movable abutment movable in line with the mixing tube that admits the pre-mixed air and fuel to idle to the main throat of the carburetor 'by passages that bypass the throttle butterfly in said carburetor.

Another feature is means for cutting olf the flow of fuel to idle from flowing through said mixing tube for fuel and air to idle.

Other patents have covered means for :cutting olf the fuel to idle at closed throttle decelerations above a predetermined speed, such as U.S. Patent No. 2,395,748, to Mallory, dated Feb. 26, 1946, entitled Degasser for Internal Combustion Engines, and U.S. Patent No. 2,809,623, to F. V. Hall, dated Oct. 15, 1957, entitled Control IDevice for Carburetor-Type Internal Combustion Engines, but they accomplish the fuel shut off in a different Way'by shutting olf the fuel to idle and the air to idle at the 'same time to greatly reduce the exhaust emissions during deceleration. 'I'his invention is an improvement in the idle mixing and shut olf with other advantageous features.

Another feature is means for cutting olf the flow of air and fuel to idle from flowing through the mixing tube for supplying fuel and air to idle, lby suitable means such as moving the abutment against the tube to act as a close olf valve.

Another feature is a suction operated motor actuated lby a valve to control engine supplied suction to supply the means for automatically cutting off the fuel to idle and the air to idle in such a carburetor when decelerating with closed throttle above predetermined engine speeds and automatically turning on Ior readmitting said idle fuel and air when the throttle is opened or when the engine speed drops below a predetermined speed.

Another feature is the provision of an auxiliary air passage much larger than the air to idle passage and automaticmeans for opening said passage to the engine intake on the engine lside of the throttle valve automatically whenever the fuel to idle is automatically cut olf. This auxiliary air admitted on the engine side of the throttle reduces the suction in the engine intake over the suction that Iwould have existed at the same engine speed if such auxiliary air were not admitted. This introduction of auxiliary air into the intake manifold reduces the oil and fumes which are sucked into the intake during such decelerations and helps dry out the intake manifold quickly by washing it out with fuel free air from said auxiliary a1r passage.

Another feature is the provision of a sandwich to go lunder a normal carburetor which sandwich receives the rich fuel and air to idle from a Ipassage in rthe carburetor and delivers it to the mixing tube wherein air is introduced from outside the carburetor to a location remote from the wall of the main air passage through said sandwich, said sandwich also including the movable abutment which shuts olf the flow of idle fuel and air by the same power that opens the auxiliary air entry path through the wall of said sandwich to the intake manifold. The auxiliary air passage is preferably much larger than the air to idle 3 path which goes through the mixing chamber for fuel and air to idle before it enters the main induction passage on the engine side of the throttle.

Another feature is a sandwich that can be used under a slightly modified carburetor for use on vehicles to be sold in smog control areas and the same carburetor without the sandwich and its controls used in non-smog control areas with no change in the modified carburetor design except possibly a changed gasket below the carburetor to close off the opening to the rich fuel and air passage from below the normally located idle fuel adjustment screw.

Another feature is a carburetor design that will operate in a normal manner and be of usual construction and cost that is adapted to be used with a smog control sandwich with automatic controls for shutting of (1) the idle fuel in high speed closed throttle deceleration (2) the idle fuel and air to idle at the same time (3) the idle fuel and opening the valve to admit auxiliary air automatically at the same time when operating at high speed closed throttle deceleration (4) the fuel to idle and air to idle both being controlled to on and off flow with the auxiliary air being turned on when the air and fuel to idle is turned olf by valves all controlled in the sandwich between the carburetor and the engine without the need of a shut off buttery in the main air passage on the engine side of the throttle butterfly.

Another feature is a design of idle fuel and air shut off controls that can be incorporated in a sandwich between the carburetor and the engine that has an adjustment when open to act as adjustment for the engine idle speed which adjustment is accessible from the exterior of the carburetor.

Another feature is the design of an auxiliary air control with the features as pointed out that can be incorporated in the carburetor or a sandwich between the carburetor and the engine as the designer may wish.

Another feature is the dual control of the richness of the fuel and air to idle by controlling the flow of rich air and fuel from the float bowl tothe idle fuel adjustment screw and other adjustable means for varying the choking of the rest of the air to idle that enters on the engine side of the carburetor butterfly without coming through the main carburetor throttle butterfly.

Another feature is means for automatically closing off the fuel valve at the entrance to the oat bowl when the idle fuel is shut off by means other than the oating effect of the float on the fuel in the oat bowl as the sloshing of the fuel in the float bowl during protracted high speed decelerations may otherwise allow excessive fuel to flow into the oat bowl.

Another feature is the use of a vacuum motor to hold up the float during fuel off decelerations to prevent the swishing of the fuel during fuel olf deceleration from building up the level of the fuel in the float bowl.

Another feature is the location of the control valves for closing off the ow of fuel and air to idle and the auxiliary air valve so that they can be easily operated by a single motor such as a suction operated diaphragm motor operating on engine intake manifold developed suction and a simple effective control circuit for the suction to the motor and bleed to the motor to get fast positive action that will shut off the fuel to idle at closed throttle above a predetermined engine speed with closed throttle and reestablish ow of the idle fuel when the throttle is closed and the engine drops below another predetermined speed.

Another feature is the control mechanism that will control the idle air and idle fuel simultaneously so that when the fuel to idle is shut off the air to idle will be simultaneously shut off.

Another feature is the control mechanism whereby the auxiliary air is opened automatically as the idle fuel is shut off.

These features give a 'better mixture of fuel and air to idle than conventional carburetors and a better shut 4 off of idle fuel and air than hitherto available and better or simpler automatic means for cutting off the fuel to idle and automatically opening the larger auxiliary air port on high speed decelerations, etc.

Other features will be more particularly pointed out in the accompanying specification and claims.

I have illustrated my invention by way of example in the accompanying drawings, in which:

FIG. 1 is an elevation section View of a carburetor and sandwich employing one form of the invention with parts in section.

FIG. 2 is a plan view of the sandwich between the carburetor and the engine shown in FIG. 1, with the controls included diagrammatically.

FIG. 3 is an enlarged elevation sectional view through Section 3 3 of FIG. 2 and a portion of associated parts.

In all figures like numerals of reference refer to corresponding parts.

In FIGS. 1, 2, and 3 I have shown a carburetor 10 having a main air passage therethrough 11. A throttle valve 12 is mounted on throttle shaft 13 and carries a throttle control arm 14. A oat bowl 15 contains a float 16 that operates a fuel inlet valve 17. Diaphragm motor 18 actuates control rod 19 to lift float 16 whenever t-he fuel to idle is shut off by means to be described.

Fuel to idle is admitted through port 21 through riser passage 22, past anti-Siphon port 23 down rich idle fuel and air passage 24, past transfer port 25 to chamber 26. Adjustment screw 27 controls the ow of rich air and fuel to idle through idle port 28 which can be used for carburetion if no smog control is required or adjustment screw 27 and port 28 can be eliminated if the carburetor is to be used with the sandwich between the carburetor and the engine intake manifold as shown for smog control.

Passage 30 goes from chamber 26 to a hole 32 in gasket 33. From hole 32 in gasket 33 a passage 34 leads to port 35. Flow through port 35 is controlled by adjustment screw 37. Rich fuel and air to idle passes adjustment screw 37 and iiows into chamber 36, then by passage 38 to port 39 in idle fuel and air mixing tube 40.

Air to idle enters through tube 48, passes through heater 46 (associated with the exhaust pipe or manifold 47), through tube 45 to chamber 42 past adjustable choke valve 43 and into mixing tube 40 past rich fuel and air port 39 and on to orifice 41 near the center of the main air Ipassage 11 on the engine side of throttle Ibutteriiy 12. The flow of the premixed fuel and air to idle abuts against movable and adjustable opening positions abutment 50 to limit the ow of fuel and air to control the idle speed of the engine. The distance of abutment 50 from opening 41 in mixing tube 40 is controlled by adjustable screw 51. Abutment 50 is mounted on reciprocally mounted shaft 53 and urged against screw 51 by spring 52. Line 48 that leads the air to idle to heater 46 may lead from the clean side of air cleaner A.

Auxiliary air port 59 in sandwich 9 leads to tube 66. Control valve 61 is of the buttertiy type and is mounted on shaft 62 and controlled by arm 63. Control of butterily 61 is by arm 63, pin 65, connecting link 64, pin 60d, arrn 60, pin 60e, connecting link 70, vacuum operated motor B containing diaphragm 71. Spring 72 bucks the action of suction on diaphragm 71 and provides the closing motion for valve 61 by the linkage just recited. When suction is applied to the spring 72 side of diaphragm 71, the spring 72 will be compressed and valve 61 opened. Lever 60 whichis pivoted to sandwich 9 at pin 67 has end 60b connected to pin 66 and connecting rod 64 at the left end, as viewed in FIG. 2. Right hand end 60a abuts against rod end 53a with a predetermined amount of lost motion. As suction on the spring side of diaphragm 71 moves valve 61 to open position, end 60a will move rod 53 to close abutment 50 against end 41 of idle fuel and air mixing tube 40. This action of abutment 50 will close ofrf ow of fuel and air through mixing tube 40 and into the main throat 77 of the sandwich 9.

One possible control circuit for the suction to motor B is shown in FIG. 2 in which line 75 goes to the valve C which includes double faced Valve 80 which is forced upward by spring 91 to close port 82 from closing olf the ow of engine developed suction from line 83. The lower face of valve 80 opens bleed port 81 when valve 80 is in this upper position, so atmospheric pressure is admitted through line 75 to the spring 72 side of diaphragm 71 so spring 72 will force valve 61 closed and abutment 50 to the open position for engine idle as adjusted by screw 51, cruise and acceleration operations, as shown in all figures.

When solenoid 90 is energized by throttle switch T being closed (when throttle 12 is closed) and series connected engine speed sensing switch G is closed as above a predetermined engine speed, the solenoid 90 will pull valve 80 down rapidly against spring 91 to close bleed port 81 and open port 82 so that engine developed suction can act on the spring 72 side of diaphragm 71 to compress spring 72 and spring 52 to close olf the air and fuel to idle from flowing through mixing tube 40 and open auxiliary valve 61. This condition prevails during a deceleration at higher engine speeds with closed throttle. The same suction between valve C and motor B can operate control rod 19 to lift the iloat 16 to close fuel valve 17 by acting on diaphragm motor 18 through line 75a.

The use of auxiliary port 59 and valve .61 may be used or not as determined by the exhaust pollutant desired or other operating conditions. Adjustment screw 44 controls idle air choke control valve 43 which with needle valve 37 (which controls the flow of rich idle fuel and air from the carburetor float bowl) combine to adjustably control the rich and lean mixture ratio of the premixed air and fuel to idle passing through tube 40 and into passage 77 of sandwich 9 and into manifold 7 of engine 8.

Suitable wiring may connect the battery 95 to ground and through the ignition switch 96 switches G and T in series to solenoid 90 and to ground, as shown in FIG. 2.

The construction shown in this invention will provide a greatly improved fuel and air mixture for idling and some or all of the cruising ranges than provided by previous carburetors. This provides better control of the smog producing unburned hydrocarbons in the exhaust of a vehicle engine in a simple desirable positive inexpensive way. The size of the tube 66, valve 61, and opening `60 can control the volume of auxiliary air admitted for best or most preferred operation. I have illustrated my inventions in these various forms; however, many other variations may be possible within the scope of this invention.

To those skilled in the art to which this invention relates many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the spirit and scope of the invention. The disclosures and description herein are purely illustrative and are not intended to be in any sense limiting.

.I claim as my invention:A

1. A carburetor for an internal combustion engine comprising a body having a main passage therethrough, a throttle valve therein, conduit means supplying a stream of idle fuel mixture in a zone adjacent the center of the passage and downstream of the throttle, abutment means adjacent the exit of said conduit means for regulating the flow of the stream from the exit of said conduit supply means, and means responsive to closed throttle operation and adapted to operate above a predetermined engine speed to adjust said regulating means to stop the ow of the idle fuel mixture.

2. A carburetor as defined in claim 1 further including means for supplying air to said passage upon adjustment of said regulating means to stop the ow of said idle fuel mixture.

3. A carburetor as defined in claim 2 wherein said air supply means comprises a conduit, a valve in `said conduit for regulating the ow of air therethrough, and a motor for operating the valve.

4. A carburetor as defined in claim 3 wherein said means to adjust the regulating means comprises a lever pivotally mounted on said body and having a free end spaced from said regulating means to provide a lost motion connection therebetween, and means connecting the lever to said motor.

References Cited UNITED STATES PATENTS 1,240,841 9/1917 Gilles 261-41 1,264,464 4/ 1918 Weld.

1,691,201 11/1928 Larkin 261-41 1,821,012 9/1931 Guthrie 261-41 2,114,655 4/ 1938 Leibing 123-97 X 2,187,885 1/1940 Markham 261-41 2,327,592 8/1943 Chisholm 261-41 2,420,786 5/1947 'Mallory 123-97 X 2,443,465 l6/ 1948 Leibing 123-124 3,201,097 `8/ 1965 Arndt 2-61--41 FRANK W. LUTTER, Primary Examiner.

HARRY B. THORNTON, Examiner.

TIM R. MILES, Assistant Examiner. 

